Fuel-supply system for engines.



O. LASCHE.

FUEL SUPPLY SYSTEM FOR ENGINES.

APFUCATION man FEB. 10. 1914.

1,15%994. Patentd Sept. 28, 1915.

3 SHEETS-SHEET Witnesses: I Inventor:

OsKar Lasclye,

4 5 His .Xlttomeg 0. LASCHE. FUEL SUPPLY SYSTEM FOR ENGINES. APPucATioN FILED FEB. to. 4.

1,154,994 v PatentedSept.2 8,1915.-

3 SHEETS-SHEET 2 It] 29 I'll-Hill I 43 Al 47 48 4e Fig.4.

- Hll Witnesses: 46 Inventor: I

Fig.5 Ostfav Lasc e, I

, His fltto rngy.

I 0. LASCHE. FUEL SUPPLY SYSTEM FOR ENGINES.

" APPLICATION FILED FE B. I0. I914.

. Patented Sept. 28, 1915' 3 SHEETS-SHEET 3.

wltnesses.

OFFICE.

OSKAR LASCHE, OF C HARLOTTENBURG. GERMANY. ASSIGNOR TO GENERAL ELECTRIC (ZOMPANY. A CORPORATION OF NEW YORK.

FUEL-$UPPLY SYSTEM FOR ENGINES.

Application filed. February 10, 1914.

oer. or by regulating the action of a bypass valve which allows a portion of the fuel to flow back to the suction chamber either at the beginning, or end of the discharge stroke of the plunger. High speed plunger pumps when called upon to continuously delH er measured and exact quantities of fuel under-high pressure are l' ahle to partial or complete failure due to inpiry.

to the parts thereof and more especially to such parts as the packings and regulating devices.

My invention aims to avoid the objections above noted. This is accomplished by employinfr a pressure tank to which an abundant supply of fuel is delivered by any suit.

able means, such as a pump, the pressure in said tank preferably but not necessarlly approximating: the final pressure of.the fuel entering the combustion chamber. Between the tank and each of the fuel injectors is a rotary gear pump which may increase the pressure somewhat but whose principal function is to act as a measuring device and determine just how much fuel shall be delivered to the injector for each working strolqe of the engine. Since the pressure ditlerenr-e between the suction and discharge sides of this pump is small the .actua'l work performed is small and the-liability of it and its regulating mechanism getting out 'of order is reduced to a minimum, and the work required of the speed governor is con respondingly reduced.

In the accompanying drawings which Specification of Letters Patent.

Patented Sept. 28, 1915. Serial 1%. 817,815.

illustrate one of the embodiments of my invention, Flgure 1 is a somewhat diagrammatic view illustrating the fuel system; Fig.

"S a sectional view A the gear pump taken on line 2+2 of Fig. 3; Fig. 3 is an axial section of the g ar pump; Figs. 4 and 5 are detailed views showing a modification of the means for driving the gear pump, and Fig. 6 is a sectional view of the fuel injector.

in Fig. 1 is shown a portion of an internal combustion engine having two cylinders 7 and. 8 which are mounted on the scavenging air receiver 9. Each cylind is provided with one or more fuel injec t hrs 10. In the present embodiment of my invention each cylinder has two injectors 10- rated on opposite sides thereof, the said in'- jectors being of any well-known or suitable construction.

T he means for su plying fuel to the injectors will now be described. 11 indicates a tank in which fuel is maintained under pressure. This can be accomplished in a a'ariety of ways. 12 indicates a fuel pump comprising a plunger 13. a cylinder 14, a suction valve 15. and a discharge valve 16. The plunger and suction valves are actuated by levers through rollers 17, said levers being actuated by the engine. On the Workin stroke of the plunger fuel is delivered to the tank 11. Any excess is returned to the source of supply 18 through the icy-pass 1 containing a spring actuated valve 20. The pump 12 should be large enough to continuously deliver to "the tank 11 all the fuel that is. required for maximum operationof the engine and need not be re gni-- lated with exactness because any excess will he returned through the by-pass or through the suction valve as is common practice.

ln order to maintain the fuel in the tank under a relativelv high pressure in the case of intermittent delivery of the main pump, a pipe 21 is provided that is connected to it and tothe manifold '32, the latter being ill communication with a source of'high pressure air commonly referred to as the blast' air. To the manifold is connected :1 storage tank or blast bottle 23. In the pipe 21 is a valve 94. by means of which the tank 11 can be cut off from the source of high pressure air.

indicates a gear pump in which a pump is provided for each fuel injector. Each pump is of the construction illustrated in Figs. 2 and 3. The pumps all receive fuel from the tank 11 by the pipe 29 and deliver it to the injectors bv the pipes 30, a single pipe running to each injector. Compressed air for injecting; the fuel is supplied by the pipes 31 that a re connected to the manifold and blast bottles. the latter being connected to a suitable compressor by the pipe 22. The gear pump is driven by a suitable means. as for example. by disk I-li with which engages a friction roller R3. said roller being splined on the shaft 4. which in turn is driven through suitable gearing from the main shaft of the engine. The position of the friction roller 33 is determined by a speed governor which acts on the roller through the governor arm Referring to Figs. 2 and 3, the measur ing pump '28 comprises a iasing and a rernm'able cover -36. In the cover is formed a suction chamber 37 that is in communication with the supply pipe 29. There are as many gear pumps as fuel injectors, each comprises a pair of gears 38 and 3!). said gears having suitable spindles. The gears of the various pumps are so arranged that one driving shaft 40 suliices for them all. Fuel is delivercd by the individual pumps to the (U11- duits 30. Tn each conduit is located a throttle valve 4-], by means of which the amount of fuel delivered by each pump to its orrespondin; fuel injector can be varied. .rs an additional means of regulation a by-pass 42 may be provided which contains a pressure actuated valve i When the valve opens. due to excess pressure. fuel is by-passed from the high prcssru'e to the low pressure side of the pump.

The means for driving the pump will now he described; Spline-d on the shaft in is a llat disk 32 which is normally held in enmun-Incl with the friction roller Ilfl hy the hoiupre -w-.iou. pring 'li. there being: a hall thrust l5 inserted between the ll indicatesthe drivdined thereon is a ski col of the Dior- 1 no rnu r l is i l a v moved toward and in i -'l a I i ilii sha: for speed o i Ire cine o. and H! of fuel i vcred by each pinup tz. jeetor "will e corrcspondingrly changed. pressure in thcclrarnhy 3i pre... i subsliaiuially the same-as that of the blast d to inject. fuel into the combusair (lllll lt-H M tion. chambers oi the engine. and hence tuc gear prn'ips will have very little work to perform. Their principal function is to accurately measure the amount of fuelv delivered to the injectors for ach firing stroke of the engine. Owing: to the fact that they have to perform. only a very small amount of work. the danger of their failing to operate properly is reduced to a minimum.

Instead of contiruiously rotating the measuring pumps, the pumps may be operated intermittently at suitable speeds as indicatcd in Figs. 1- and 5. ()n the shaft 40 is mounted a ratchet 46 which is reciprocated by any suitably governed means through the rod -17. The end of the rod 'arrics a pawl 48 that is spring pressed into engagement with the teeth on the ratchet to. A spring pressed detent 4-1) is employed to prevent backward rotation of the ratchet. Such an arrangement causes the supply of fuel to the engine to be delivered intcrmittently.

In order to temporarily cut off the source of fuel supply from the injector during certain parts of the working strokes of the eugine pistons the arrangement shown in Fig (3 is provided. 51 indicates a needle valve, 52 perforated washers. and 53 a sad for the washers having peripheral passages delivering into outlet 54-. The needle 'alve passes through a suitable stuffing box and is actuated by the lever 55 which is moved by some part of the engine in any suitable or well-known manner. 56 indicates a coiled compression spring; that tends to hold the needle uilve on its seat. The needle valve also enlarged to form a slide valve 57, there being; passages 58 through it. (oinpressed air from the blast bottle is admitted by the pipe fl and fuel is admitted by the pipe 30. In the pipe 30 a receptacle 5!) containing air under relatively high pressure. this air being obtained from the pipe Ill and passes through the pipe (30. the latter containing a nou-return valve (ll. \Vheu the needle and slide valves are in the positions shown fuel from the pipe 30 can be delivered to the upper side of the valve. 57 and Will flow thr ugh the passages 38 on to the upper perforated washer. Just as soon. l'iou'ever. as the needle valv is opened the slide valve covers the port rouununidine; with the pipe 30 and further admission of fuel cut oil'. il during the in teraal the fuel pipe 30 is closed the puu'ip continues to deliver fuel ir in the re eptacle 59 will he com- ,d by an amount sullieient to admit the fuel to the receptacle and as soon as the valve 57 is opened the said air pressure Will room-rate with the pump to force fuel into the injector.

Ill]

injected by compressed air out it is also applicahle' to engines in which such air or gaseous medium is omitted. In such a case the pressure within the tank 11 should correspond, ,or substantially correspond, to the pressure prevailing in the injection device.

My apparatus has the advantage that it can easily be kept in continuous and reliable Working condition since the packing of the gear pump causes little difiiculty on the one hand and exact regulation of the main pump is avoided on the other hand. Further, since the measuring pump is of the rotary type, thh driving mechanism can he made simpler than for a reciprocating pump. Also the regulation of such pumps is acornparatively simple matter.

I have shown What I consider to be the best form of rotary measuring pump, but

the invention is not limited to the specific form shown unless so specified in the claims.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the 'best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. The combination With a high compression internal combustion engine having separate points of fuel injection, of a blast air bottle, a fuel tank, a pipe connecting the tank tov the bottle, a plunger pump arranged to deliver fuel to the tank against the pressure of the blast air in amounts s1 tficient to supply the demands of the engine, a measuring pump for each of said points of injection, said pumps receiving fuel in common from the tank and delivering it in,-

I dependently to said fuel injection points.

and means for varying the amount of fuel deli vered by each pump to the point of consumption, an means connecting the blast air bottle to each fuel injection point.

2. The comhinationwith a high compression multi-cylinder internal combustion engine having a fuel injector for each cylinder, of ablast air bottle, a tank, a pipe connecting the tank tothebottle, a, pump for supplying fuel. to the tank againstthe pressure of the blast air, measuring pumps which receive fuel in common from the pressure tank and deliver it independently to the injectors, means for simultaneously driving the measuring pumps, means for changing the effective delivery of the latter pumps, and means connecting the blast air bott e tothe fuel injectors.

3. The combination pf av high compression internalcomligstiorilengine, an injector gas pressure, a measuring pump that receives '1 fuel under pressure from the fuel tank and delivers it to the injector, and means for varying the amount of fuel delivered by the measuring pump.

4. The combination of a multi-cylinder internal combustion engine, a fuel injector for each cylinder, a tank, a pump for sup plying fuel thereto and maintaining a suitable pressure, a measuring device comprising a plurality of geared pumps all of which receive their fuel in common from the tank, each of said pumps delivering -a measured quantity of fuel to its corresponding injector, a means common'to the pumps for driving them, and means for varying the speed of the pumps to regulate their delivery. V

5. The combination of an internal combustion engine, a fuel injector therefor. a tank containing fuel under pressure, a main )ump for upplying fuel thereto, a measuring pump which receives high pressure fuel from the tank and delivers it to the injector, driving means for the pumps; and a by-pass on the discharge side of the measuring pump for controlling its effective delivery to the injector.

6. The combination of an internal combustion engine, a fuel injector therefor. a tank containing fuel under pressure, a main pump fer supplving fuel therctfi, a measuring pump which receiyes high pliessure fuel from the tank and dehvers it to the injector, driving means for the pumps, a bypass on the'discharge side of the measuring pump, and a throttle Yalve located in the discharge conduit of the measuring pump to throttle its delivery to the injector.

"2'. The combination of an internal comloustion engine, a fuel injector therefor. a tank tontaining fuel under pressure. a main pump for supplying fuel thereto. a measuring pump which receives high pressure fuel from the tank and delivers it to the in ector, a friction driving means for the measuring pump which is actuated by the engine, 'a means for varying the relation between the driving and the driven parts of said pump to change its speed, and a driving means for the main pump.

8. The combination of an internal combustion engine. a fuei tank, a pump for supplying fuel. under pressure thereto,ameasuring pump driven by the engine which receives its supplv under pressure from the tank, a fuel injector comprising a casing,

means for atomizing the fuel, and a needle valve, a conduit admitting high pressure air to "the casing, a conduit admitting fuel to the casing, a receiver in the fuel conduit which subjected to said air pressure, and a valve iuombie with the needle valve to prevent the passage of fuel from the conduit into the naming when said needle valve is open.

OSKAR LASCHE.

Witnesses:

WQLDEMAR HAUPT, HENRY HAsPER. 

